<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">
    <meta name="apple-mobile-web-app-capable" content="yes">
    <title>OpenLayers Game: Bounce Ball</title>
    <link rel="stylesheet" href="../theme/default/style.css" type="text/css">
    <link rel="stylesheet" href="style.css" type="text/css">
    <script src="../lib/OpenLayers.js?mobile"></script>
    <style type="text/css">
      html, body { height: 100%; }
      #shortdesc { display: none; }
      #tags { display: none; }
    </style>  

    <script type="text/javascript">
        var map, vlayer;
        function adjustLocation(delta, feature) {
            feature.geometry.move(delta.x, delta.y);
            var me = map.maxExtent; 
            var rad = 6;
            if (feature.geometry.x > (me.right - rad)) { 
                feature.geometry.x = me.right - rad;
            } else if (feature.geometry.x < (me.left+rad)) {
                feature.geometry.x = me.left+rad;
            } 
            if (feature.geometry.y > (me.top-rad)) {
                feature.geometry.y = me.top-rad;
            } else if (feature.geometry.y < (me.bottom+rad)) {
                feature.geometry.y = me.bottom+rad;
            }    
            vlayer.drawFeature(feature);
        }
        function init() {
            map = new OpenLayers.Map( 'map', 
                {
                 'maxExtent': new OpenLayers.Bounds(0, 0, $("map").clientWidth, $("map").clientHeight), 
                 controls: [], 
                 maxResolution: 'auto'} 
            );
            var layer = new OpenLayers.Layer("",
                    {isBaseLayer: true} );
            map.addLayer(layer);
            map.zoomToMaxExtent();
            vlayer = new OpenLayers.Layer.Vector();
            var feature = new OpenLayers.Feature.Vector(
                new OpenLayers.Geometry.Point(map.getCenter().lon, map.getCenter().lat));
            vlayer.addFeatures(feature);    
            map.addLayer(vlayer);
            if (window.DeviceMotionEvent) {
                window.addEventListener('devicemotion', function (evt) {
                    var delta = null;
                    if (typeof(evt.accelerationIncludingGravity) != 'undefined') {
                        delta = {
                            'x': evt.accelerationIncludingGravity.x * 3,
                            'y': evt.accelerationIncludingGravity.y * 3,
                            'z': evt.accelerationIncludingGravity.z
                        }    
                    }
                    adjustLocation(delta, feature);
                }, true);    
            } else {
                alert("This demo does not work on your browser.");
            }    
        }
    </script>
  </head>
  <body onload="init()">
    <h1 id="title">Accelerometer Example</h1>
    <div id="tags">
      mobile, game
    </div>  
    <div id="shortdesc">Simple acceleration demo; roll a vector feature around
    on a map. (Only tested on iOS 4.)</div>

    <div id="map" width="100%" height="100%" style="background-color: gray"></div>
    <div id="docs">
      <p>Demo works best when device is locked in portrait mode.</p> 
    </div>
  </body>
</html>
